Alternate Energy is Blowing in the Wind

The wind pushes on things. It's a FORCE! If you live where I live (near one of the largest "windmill farms" in California), you see a lot of evidence that the wind blows a lot here (and no, it's not because we're close to Sacramento where the politicians talk a lot --grin--)--many of the trees and other plants in our area have what's called the "(put the name of your town here) lean". In other words, the trees all lean away from the usual incoming direction of the wind. The winds here are steady--and thus make this area a prime location for harnessing this constant force. Force = energy. (Basics from Physics Class here)

The linear motion of the wind pushes against the blades or wind-capturing structures and is usually converted to a circular motion.

For a mechanical function, such as grinding grain or pumping water (or air), the circular motion is translated directly to the circular millstones to grind the grain or is converted to up-and-down reciprocating motion to pump the water (unless it's a screw-type pump, in which it maintains the circular motion). These types of mechanical uses take the motion provided by the wind at the top of the tower and transfer that motion to be applied at the base of the tower.

For electrical generation, however, there's no need for the motion to be transferred down to the base of the tower. The work (or application) takes place at the axle of where the wind-capturing structures are. As the axle rotates, electricity is generated.

How is Electricity Generated?

Think about an electric fan. It's got blades like a windmill, right? You plug it in to an electrical socket and switch it on (or, if it's a battery-operated device, you just switch it on). Well, when the electricity (electrons) flowing from the socket comes through the wires to the wiring coils surrounding the magnets attached to the shaft of the blades, they cause a magnetic field that pushes the magnets on the shaft away from the moving current in the coils--thus moving the blades and "blowing air". (That's what a fan does, right?) An electricity-generating windmill does this process in reverse--it takes the motion of the blades to turn the shaft on which are mounted powerful magnets. The moving magnets turn within an enclosure of coils of wires. When the fields from the magnets move, they cause the electrons in the wire coils to also move--to the point that the "pressure" builds up and the electrons (aka "electricity") flows down through the wires to the transmission lines and into the power grid and on to your house or business. (There's a good chance that there are also control devices --things like power transformers, regulators, and smoothing apparatus to keep the power "clean".) But at least this explains the "basics" of how the wind-generating process works. You can read the books and other more detailed materials presented in this lens to get more information and help with setting up your own new power source!

Although most of us are familiar with the windmills that resemble the blades of an airplane propeller, you can also find windmills that resemble egg-beaters (they are called Vertical Axis Wind Turbines--VAWT), and those that resemble cups or barrels (also usually on a vertical axis and thus considered VAWT).

But research continues on aerodynamic designs for improving efficiencies of the wind-capturing devices--unique designs are being produced that may solve all sorts of logistics and engineering problems.